Problem: Reduce to simplest form. $ -\dfrac{3}{7}+\left(-\dfrac{3}4\right)=$
Explanation: $=-{\dfrac{3 \cdot 4}{7\cdot4}} - {\dfrac{3\cdot7}{4\cdot7}}$ $=-{\dfrac{12}{28}}-{\dfrac{21}{28}}$ $=-\dfrac{33}{28}$ or $-1\dfrac5{28}$